212 BULLETIN 13L, UNITED STATES NATIONAL MUSEUM 



WASHINGTON AND ADAMS COUNTIES 



Veins carrying manganese oxides occur along Snake River about 

 20 miles below Huntington. The ore is low grade and siliceous, with 

 a quartz and jasper gangue. Several claims were actively prospected 

 during the war demand without revealing important bodies of 



manganese ore. 20 



PSILOMELANE, variety WAD 



The material called wad, and commonly regarded as a variety of 

 psilomelane, occurs at one locality in Idaho as rather unusually good 

 material which merited a detailed examination the results of which 

 are here presented. 



BLAINE COUNTY 



A specimen of wad sent to the National Museum for identification 

 by B. A. Smith, of Martin, is from his property in the Lava Creek 

 mining district 20 miles west of Arco. The material is rather soft 

 and sectile and, although compact and tough, can be marked with 

 the finger nail, which leaves a black lustrous metallic mark. It has 

 a dark-brown color and, from its color, might be supposed to be a 

 slightly manganiferous limonite. It is exceedingly light, large pieces 

 floating for a time on water, although they gradually absorb water 

 and sink. An analysis of this specimen gave the following results : 



Analysis of wad from Blaine County 



(E. V. Shannon, analyst) 

 Constituent Per cent 



Insoluble portion and separated silica 5. 80 



Ferric oxide (Fe 2 3 ) 3. 04 



Manganous oxide (MnO) 55. 90 



Lime (CaO) S. 86 



Oxygen (O) in excess of MnO 11. 74 



Water (H 2 0) above 110° C 11. 60 



Water (H 2 0) below 110° C 4. 10 



Total 101.04 



The material is completely amorphous and there is no means of 

 determining whether it represents a homogeneous substance or a 

 mixture of several fine-grained minerals. For this reason no definite 

 formula can be derived from the analysis. 



PSILOMELANE, variety ASBOLITE 



LEMHI COUNTY 



The name asbolite is applied to material usually considered to be 

 wad containing oxide of cobalt. Umpleby states, under asbolite. 

 that earthy cobalt oxide, more or less contaminated with other 

 oxides, occurs in cracks and crevices in the cobalt-nickel ores of the 



20 D. C. Livingston. Univ. of Idaho, School of Illinois, Bull. 2, pp. 32-34, 1919. 



